Detecting Hidden Leakages

Reducing the entropy of the mask is a technique which has been proposed to mitigate the high performance overhead of masked software implementations of symmetric block ciphers. Rotating S-box Masking (RSM) is an example of such schemes applied to AES with the purpose of maintaining the security at least against univariate first-order side-channel attacks. This paper examines the vulnerability of a realization of such technique using the side-channel measurements publicly available through DPA contest V4.